SESSION TITLE: Infectious Diseases Cases I
SESSION TYPE: Affiliate Case Report Slide
PRESENTED ON: Tuesday, October 27, 2015 at 07:30 AM - 08:30 AM
INTRODUCTION: Mycobacterium abscessus is a non-tuberculous mycobacteria (NTM) capable of causing soft tissue infections and invasive disease in patients with anatomical abnormalities (e.g. bronchiectasis) or prosthetic implants. We report a fatal case of native valve M. abscessus endocarditis.
CASE PRESENTATION: A 59 year old man presented with weakness, dizziness and weight loss. There was no history of recent intravascular catheterization or prosthetic implants. Physical exam was remarkable for fever, tachycardia and a systolic ejection murmur. Blood cultures on initial presentation were positive for Gram-variable rods, which were later identified as acid-fast bacilli. Transthoracic echocardiogram showed severe regurgitation of the aortic valve with flail motion concerning for vegetations. The patient was started on clarithromycin, cefoxitin, moxifloxacin and tigecycline for concern of rapidly growing Mycobacterial infection. Mycobacterial bacteremia persisted despite aggressive antimicrobial therapy. The patient suffered rapid deterioration with respiratory failure and shock. Transesophageal echocardiogram revealed a 5.5 x 3.6 mm vegetation with malcoaptation and perforation of the aortic valve cusps causing severe “wide-open” regurgitation. The clinical picture rapidly evolved into refractory shock with multi-organ failure and death. The circulating NTM was ultimately identified as Mycobacterium abscessus.
DISCUSSION: M. abscessus has been established as a source of endocarditis in patients with surgical prostheses, such as heart valves, bypass grafts and intravascular catheters. Native valve endocarditis due to M. abscessus is rare, and the optimal treatment strategy is unknown. This species of NTM is capable of causing rapid valve destruction, usually resulting in fatal outcomes. Due to clinician unfamiliarity with this disease, diagnosis is often delayed, and the window for timely medical and surgical intervention may be lost.
CONCLUSIONS: Mycobacterium abscessus is an uncommon cause of rapidly progressive native valve endocarditis. A high index of suspicion is required for timely diagnosis. Early surgical intervention could be a key factor associated with better outcomes.
Reference #1: Corrales-Medina V, Concha R, Simkins J, et al. Native valve endocarditis caused by rapidly growing mycobacteria: case report and review of the literature. Scand J Infect Dis. 2007; 39: 639-641.
Reference #2: Tsai WC, Hsieh HS, Su HM, et al. Mycobacterium abscessus endocarditis: a case report and literature review. Kaohsiung J Med Sci. 2008; 24: 481-486.
DISCLOSURE: The following authors have nothing to disclose: Van Hoang, Alfredo Arauco-Brown, Diana Guerra
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